Intrinsic Oscillations and Multistability in the Trasmission of a Na Vapor filled Fabry-Perot in absence of a Buffer Gas.

In previous experiments on the trasmission properties of a Fabry-Perot interferometer filled with Na vapor |1,2| a buffer gas was added to collisionally broaden the resonance, with velocity changing collisions inducing broad ground state pumping over the whole line. Here we consider the very different inhomogeneous regime (no buffer gas), where optical pumping takes place on single homogeneous velocity groups. We carefully control direction and strength of the magnetic field and examine the cavity transmission properties, both in intensity and polarization, in the temperature range 130 - 180 °C (0.5 - 9.2·1011 atoms/cm3), as the laser is tuned across the DI line.